Specific Aims: Aim 1: The primary aim is to assess Clozapine treatment by race in clinical trials as compared to real-world treatment settings for those with schizophrenia. The primary hypothesis is that African-Americans will be under represented in clinical trials as compared to the population typically treated with Clozapine. I also hypothesize that Clozapine use in both real-world settings and clinical trials will be underutilized in minority populations. Aim 2: Baseline symptoms and clinical variables will be examined by race between clinical trial participants and patients treated in routine settings. I hypothesize that people with schizophrenia who are treated in the real-world will have more severe symptomatology such as positive, negative and anxious behavior that are often excluded from clinical trials. Aim 3: Treatment response will be compared by race between the treatment settings with Clozapine. It remains unknown how Clozapine response compares between the real-world settings and clinical trials, particularly with regard to race since clinical trials typically have enrolled low numbers of African-Americans. I hypothesize that response to Clozapine by race will be similar across settings after controlling for baseline differences.